hart smith



ttnitet swat O. HART SMITH, OF BALTIMORE, MARYLAND.

Letters Patent No. 101,406, dated March- 29, 1870.

The Schedule referred to in these Letters Patent and making part of thesame To all whom it may cancer-u Be it known that I, O. HART SMITH, ofBaltimore, in the county of Baltimore and State of Maryland, haveinvented certain Improvements in Process of Preparing Paper for Roofingand Similar Purposes, of which the following is a specification.

My invention relates to processes of treating paper for roofing,sheathing, and similar purposes, and consists in saturating the paper insheets, of any desired length, with a heated compound of coal-tar,wood-tar, and dead-oil of coal-tar, and then passing it through heavymetallic presser-rolls, for the purpose of thoroughly incorporating thecompound with the paper, and of leaving it in a suitable condition foralmost immediate. rolling into rolls for storage or transportation.

In preparing paper for roofing, sheathing,,and similar purposes, I havefound that when it was satur ated with heated coal-tar alone, itssurface possessed a. certain gummy or sticky quality, and-that whenrolled up, its surfaces would in a little time adhere so closelytogether as to render it impossible to unroll it without positive injuryto the paper, and that; in warm weather or when exposed to any unusualheat, it would become a. compact mass.

The object of my invention is to produce a paper prepared for roofing orsheathing free from these objections.

To accomplish this,'I take acertain quantity of coal-tar, and add aboutone-sixth of its quantity of wood-tar, such as is usually produced atthe fac toriesof dye-stuffs, and also about one-sixth of its quantity ofdead-oil obtained by the distillation of coal-tar.

This mixture I heat to the boiling point, and then pass the paperthrough it, allowing it to remain long enough in the mixture to becomecompletely saturated with it, and afterward pass it through heavymetallic or other suitable pressure-rollers, for the purpose ofthoroughly incorporating the mixture with the fiber of the paper.

\Vhen the paper is in long sheets it may for convenience be first rolledup, and then, as unrolled, be passed through the mixture, and then onthrough the pressure-rollers.

After the paper comes from the. pressure-rollers it can be rolled upready for storage or transportation almost immediately, as its surfacewill be found to be free from any gummy or sticky quality, owing to theeffect of the wood-tar and dead-oil on the mixture, and the body of thepaper, by reason of its severe pressure in the rollers or between them,will be found con'iparatively dry.

In this way I make an excellent and durable preparation of paper insheets or rolls for roofing, sheathing and similar purposes.

Having thus described my invention,

What I claim, is y The combination of coal-tar, wood-tar, and deadoil,in the proportions herein described for preparing paper for roofingpurposes, in the manner herein set forth.

0. HART SMITH.

Witnesses H. B. Moss, PHIL. '1. Donna.

